Percutaneous coronary intervention using new-generation drug-eluting stents versus coronary arterial bypass grafting in stable patients with multi-vessel coronary artery disease: From the CREDO-Kyoto PCI/CABG registry Cohort-3

Aims

There is a scarcity of studies comparing percutaneous coronary intervention (PCI) using new-generation drug-eluting stents (DES) with coronary artery bypass grafting (CABG) in patients with multi-vessel coronary artery disease.

Methods and results

The CREDO-Kyoto PCI/CABG registry Cohort-3 enrolled 14927 consecutive patients who underwent first coronary revascularization with PCI or isolated CABG between January 2011 and December 2013. The current study population consisted of 2464 patients who underwent multi-vessel coronary revascularization including revascularization of left anterior descending coronary artery (LAD) either with PCI using new-generation DES (N = 1565), or with CABG (N = 899). Patients in the PCI group were older and more often had severe frailty, but had less complex coronary anatomy, and less complete revascularization than those in the CABG group. Cumulative 5-year incidence of a composite of all-cause death, myocardial infarction or stroke was not significantly different between the 2 groups (25.0% versus 21.5%, P = 0.15). However, after adjusting confounders, the excess risk of PCI relative to CABG turned to be significant for the composite endpoint (HR 1.27, 95%CI 1.04–1.55, P = 0.02). PCI as compared with CABG was associated with comparable adjusted risk for all-cause death (HR 1.22, 95%CI 0.96–1.55, P = 0.11), and stroke (HR 1.17, 95%CI 0.79–1.73, P = 0.44), but with excess adjusted risk for myocardial infarction (HR 1.58, 95%CI 1.05–2.39, P = 0.03), and any coronary revascularization (HR 2.66, 95%CI 2.06–3.43, P<0.0001).

Conclusions

In this observational study, PCI with new-generation DES as compared with CABG was associated with excess long-term risk for major cardiovascular events in patients who underwent multi-vessel coronary revascularization including LAD.

Modifiers of the Risk of Diabetes for Long-Term Outcomes After Coronary Revascularization: CREDO-Kyoto PCI/CABG Registry

BACKGROUND

Diabetes is a well-known risk factor for adverse outcomes after coronary revascularization.

OBJECTIVES

This study sought to determine high-risk subgroups in whom the excess risks of diabetes relative to nondiabetes are particularly prominent and thus may benefit from more aggressive interventions.

METHODS

The study population consisted of 39,427 patients (diabetes: n = 15,561; nondiabetes: n = 23,866) who underwent first percutaneous coronary intervention (n = 33,144) or coronary artery bypass graft (n = 6,283) in the pooled CREDO-Kyoto PCI/CABG (Coronary Revascularization Demonstrating Outcome Study in Kyoto Percutaneous Coronary Intervention/Coronary Artery Bypass Graft) registry. The primary outcome measure was major adverse cardiovascular and cerebral endpoints (MACCE), which was defined as a composite of all-cause death, myocardial infarction, and stroke.

RESULTS

With median follow-up of 5.6 years, diabetes was associated with significantly higher adjusted risks for MACCE. The excess adjusted risks of diabetes relative to nondiabetes for MACCE increased with younger age (≤64 years: adjusted HR: 1.30; 95% CI: 1.19-1.41; P < 0.001; 64-73 years: adjusted HR: 1.24; 95% CI: 1.16-1.33; P < 0.001; >73 years: adjusted HR: 1.17; 95% CI: 1.10-1.23; P < 0.001; P _interaction < 0.001), mainly driven by greater excess adjusted mortality risk of diabetes relative to nondiabetes in younger tertile. No significant interaction was observed between adjusted risk of diabetes relative to nondiabetes for MACCE and other subgroups such as sex, mode of revascularization, and clinical presentation of acute myocardial infarction.

CONCLUSIONS

The excess risk of diabetes relative to nondiabetes for MACCE was profound in the younger population. This observation suggests more aggressive interventions for secondary prevention in patients with diabetes might be particularly relevant in younger patients.

Comparison of Outcomes of Percutaneous Coronary Intervention Versus Coronary Artery Bypass Grafting Among Patients With Three-Vessel Coronary Artery Disease in the New-Generation Drug-Eluting Stents Era (From CREDO-Kyoto PCI/CABG Registry Cohort-3)

There is a scarcity of data comparing long-term clinical outcomes between percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG) in patients with three-vessel coronary artery disease (3VD) in the new-generation drug-eluting stents era. CREDO-Kyoto PCI/CABG registry Cohort-3 enrolled 14927 consecutive patients who had undergone first coronary revascularization with PCI or isolated CABG between January 2011 and December 2013. We identified 2525 patients with 3VD (PCI: n = 1747 [69%], and CABG: n = 778 [31%]). The primary outcome measure was all-cause death. Median follow-up duration was 5.7 (interquartile range: 4.4 to 6.6) years. The cumulative 5-year incidence of all-cause death was significantly higher in the PCI group than in the CABG group (19.8% vs 13.2%, log-rank p = 0.001). After adjusting confounders, the excess risk of PCI relative to CABG for all-cause death remained significant (HR, 1.45; 95% CI, 1.14 to 1.86; p = 0.003), which was mainly driven by the excess risk for non-cardiovascular death (HR, 1.88; 95% CI, 1.30 to 2.79; p = 0.001), while there was no excess risk for cardiovascular death between PCI and CABG (HR, 1.19; 95% CI, 0.87 to 1.64; p = 0.29). There was significant excess risk of PCI relative to CABG for myocardial infarction (HR, 1.77; 95% CI, 1.19 to 2.69; p = 0.006), whereas there was no excess risk of PCI relative to CABG for stroke (HR, 1.24; 95% CI, 0.83 to 1.88; p = 0.30). In conclusion, in the present study population reflecting real-world clinical practice in Japan, PCI compared with CABG was associated with significantly higher risk for all-cause death, while there was no excess risk for cardiovascular death between PCI and CABG.

Successful Treatment of Cardiac Tamponade due to Rupture of the Heart Performing an Open-chest Pericardiotomy

A 78-year-old woman with mild dementia was found unconscious by her family. She was transported by an ambulance to our emergency room (ER). Initially, she was comatose and in a state of shock. The echocardiographic findings suggested cardiac tamponade by hematoma. Computed tomography also showed tamponade without aortic dissection. After imaging, she went into cardiac arrest, was returned to the ER, and tracheal intubation and left thoracotomy for pericardiotomy were performed. A return of spontaneous circulation was obtained by following this procedure. Bleeding from a rupture of the left cardiac free wall was confirmed, and the rupture was closed with TachoSil®. After closing the thoracotomy, electrocardiography revealed ST elevation in the precordial leads. Subsequently, placement of an indwelling intra-aortic balloon pump and coronary angiography (CAG) were performed. CAG showed an occlusion of the anterior interventricular branch and circumflex branch of the left coronary artery. She underwent conservative therapy in a coronary care unit. Finally, after obtaining hemodynamic stability and baseline mental status, she was transferred to another medical facility. We herein report a rare case involving the successful treatment of cardiac tamponade due to rupture of the heart performing an open-chest pericardiotomy and additionally discuss the key points for obtaining a favorable outcome.

AORTIC INJURY DUE TO PARAGLIDING: A CASE REPORT

A 64-year-old male fell from an altitude of 10 m while paragliding after stalling due to the wind. The purpose of this case report is to describe the outcomes after multiple injuries sustained during a paragliding accident, including a potentially life-threating injury to the thoracic aorta. The subject sustained a bite wound on his tongue, injuries to his chest (left side) and back, and a right forearm deformity. Enhanced whole body computed tomography (CT) revealed fractures of the bilateral laminae of the second and third cervical bones, right first rib, the tenth thoracic vertebral body (compression type), second lumbar vertebral body (burst type) and the right radius, Other injuries included an injury to the thoracic aortic arch and the presence of intraabdominal fluid collection without perforation of the digestive tract. Endovascular treatment was selected for the aortic injury because of multiple injuries. Immediate management included hypotensive rate control therapy using calcium and a beta blocker. On the fourth hospital day, the subject underwent deployment of a stent-graft to the aorta and subsequent surgical immobilization for the lumbar burst fracture. He also underwent surgical immobilization of the radial fracture and was discharged on the 28th hospital day. First responders or physicians should consider the possibility of aortic injury when treating patients who suffer falls while paragliding and provide appropriate management. Failure to provide appropriate management of an aortic injury could result in death.

LEVEL OF EVIDENCE

4.

Safety advantage of modified minimally invasive cardiac surgery for pediatric patients

Minimally invasive cardiac surgery (MICS) using a small surgical incision in children provides less physical stress. However, concern about safety due to the small surgical field has been noted. Recently, the authors developed a modified MICS procedure to extend the surgical field. This report assesses the safety and benefit of this modified procedure by comparing three procedures: the modified MICS (group A), conventional MICS (group B), and traditional open heart surgery (group C). A retrospective analysis was performed with 111 pediatric patients (age, 0-9 years; weight, 5-30 kg) who underwent cardiac surgery for simple cardiac anomaly during the period 1996-2010 at Juntendo University Hospital. The modified MICS method to extend the surgical view has been performed since 2004. A skin incision within 5 cm was made below the nipple line, and the surgical field was easily moved by pulling up or down using a suture or a hemostat. The results showed no differences in terms of gender, age, weight, or aortic cross-clamp time among the groups. Analysis of variance (ANOVA) indicated significant differences in mean time before cardiopulmonary bypass (CPB), CPB time, operation time, and bleeding. According to the indices, modified MICS was similar to traditional open surgery and shorter time or lower bleeding volume than conventional MICS. No major mortality or morbidity occurred. In conclusion, the modified MICS procedure, which requires no special techniques, was as safe as conventional open heart surgery and even reduced perioperative morbidity.

Mid-term results for the Maze procedure in patients with non-mitral valvular atrial fibrillation

BACKGROUND

The Maze procedure in patients without mitral valve disease remains controversial, because of the increased invasiveness and operation time required to create additional incisions in the atria. The aim of this study was to assess prognosis following the Maze procedure in patients without mitral valve disease.

METHODS AND RESULTS

One hundred and seven consecutive patients who underwent the Maze procedure between 2002 and 2008 was enrolled in this study. Patients were divided into two groups based on the presence or absence of mitral valve disease. Freedom from atrial fibrillation was compared by multivariate logistic regression analysis at discharge. The Kaplan-Meier method and Cox-proportional hazard analysis adjusted for other predictors were estimated to compare freedom from atrial fibrillation at follow-up. Follow-up was 98% complete and mean duration of follow-up was 457 days. Operation and aorta cross-clamp times were similar between groups. No differences were identified in freedom from atrial fibrillation at discharge (non-mitral valve surgery, 55% vs. mitral valve surgery, 66%) or follow-up (57% vs. 61%, respectively). In multivariate Cox proportional hazard modelling, the presence of mitral valve disease was not associated with a poor success rate of conversion.

CONCLUSIONS

Results of the Maze procedure for atrial fibrillation without mitral valve disease were acceptable. The Maze procedure could be a beneficial option for these patients to avoid adverse events of atrial fibrillation.

Reconsiderations of mitral stenosis: rheumatic mitral valve repair and the Wilkins score

BACKGROUND

Mitral valve repair is a feasible treatment option in patients with rheumatic mitral valve disease, but it is not always successful. Mitral valve replacement is generally the surgical treatment of choice in such patients. We aimed to examine whether the Wilkins score can predict the feasibility of surgical repair in such patients.

METHODS

Mitral valve surgery was performed on 14 patients by the same surgeon (A.A.). Five patients underwent mitral valve repair (group I), and nine patients underwent mitral valve replacement (group II). The Wilkins scores were determined by assessing echocardiography findings. The selection of mitral valve repair or replacement was based on the intraoperative findings and the preferences of the same surgeon (A.A.). In group I, we performed chordal reconstruction, augmentation of the posterior leaflet, resection of chordae, decalcification of the commissure, commissurotomy, slicing of the anterior leaflet, division of the papillary muscle, and ring annuloplasty in various combinations.

RESULTS

There were no significant differences between the two groups with regard to any component of the preoperative Wilkins score. There was no significant difference in the pre- and postoperative scores in group I; however, the mitral valve orifice area was significantly improved after the operation (pre- and postoperative mean values: 1.3 ± 0.3 and 2.0 ± 0.4, P < 0.05).

CONCLUSION

Mitral valve repair is effective in treating rheumatic mitral stenosis. However, the Wilkins score may not be useful in predicting the feasibility of mitral repair.

Echocardiographic assessment of the effects of mitral valve repair on mitral valve geometry in rheumatic mitral stenosis

BACKGROUND AND AIM OF THE STUDY

While mitral valve replacement is generally considered as the standard surgical treatment for rheumatic mitral stenosis (MS), mitral valve repair may be an alternative therapeutic option. Several techniques have been used to overcome the anatomic difficulties involved in the repair of a rheumatic mitral valve. In the present study, quantitative echocardiography was used to investigate the effects of mitral valve repair and the influence of surgical procedures on mitral valve geometry in patients with rheumatic MS.

METHODS

Mitral valve repair was successfully performed in seven patients with MS, by the same surgeon. Ring annuloplasty and slicing of the anterior mitral leaflet (AML) were performed in all patients. Concomitant surgical techniques included commissurotomy, decalcification, chordal resection, and division of the papillary muscles. The preoperative and postoperative echocardiographic findings in these patients were compared.

RESULTS

The thickness of both the AML and posterior mitral leaflet (PML) (p = 0.01 for both), the opening angles of the AML (p = 0.02) and PML (p = 0.01), and the closing angle of the PML, the extent of calcification in the AML, and the pressure half-time (PHT) (p = 0.03 for all three parameters) were all significantly improved after mitral valve repair.

CONCLUSION

In the present study, the transmitral peak velocity and mean pressure gradient were not significantly changed after mitral valve repair, whereas the PHT showed a marked improvement. Hence, the PHT may represent a suitable marker for evaluating the efficacy of mitral valve repair for MS.

The Use of Enclose(®)II Anastomosis Assist Device for the Proximal Coronary Branch Anastomosis to Vascular Graft

We used the Enclose(®)II anastomosis assist device (Novare Surgical Systems, Inc., CA, USA), which was originally developed as an ancillary device for proximal anastomosis in off-pump coronary artery bypass grafting (OPCAB), to assist anastomosis for the vascular grafts without clamping those conduits in two cases. In these cases, it was difficult to clump vascular graft partially, because vascular graft was short. So we used Enclose(®)II anastomosis assist device for these cases. The advantage of this method is that the Enclose(®)II anastomosis assist device facilitates the anastomosis of arterial side branches to the artificial graft (1) by eliminating the use of partial clamp on the artificial conduits and (2) by providing a plane surface for easy handling for suture.

[Aortic root replacement as redo operation]

Aortic root replacement (ARR) after aortic valve replacement (AVR) or ARR is often a major challenge. We performed 12 cases (7 men and 5 women) of ARR as redo operation from July 2002 to June 2009 in our institution. There was no mortality. Among them. ARR was performed in 5 cases, and AVR in 6 cases, at the previous operation. The age at the redo operation was 59.6 +/- 12.7 years. The mean interval between the previous and the redo operations was 6.8 years. In the cases of previous AVR, enlargement of the aortic root or the Valsalva sinus was recognized in 3, artificial valve failure with pannus formation below the valve was in 2, and perivalvular and regurgitation with infection was in 1. In the cases of previous ARR, surgical site infection was seen in 4, among which pseudoaneurysm formation or bleeding from the suture line at the aortic root was the reason for the redo operation in 3 cases. Pseudoaneurysm formation and artificial valve failure may be involved in some type of infection. ARR may be necessary in patients with aortitis.

EuroSCORE predicts postoperative mortality, certain morbidities, and recovery time

EuroSCORE (European System for Cardiac Operative Risk Evaluation) used for calculating the risk of the postoperative mortality rate for patients undergoing open-heart surgery may be able to predict postoperative complications as well. Consecutive cases of isolated on-pump coronary artery bypass grafting (CABG) (n=1552) performed between 1991 and 2006 at our hospital group were placed into a systematic database. Patients were stratified using additive EuroSCORE. Incidence of postoperative mortality, morbidity (bleeding, heart failure, mediastinitis, pneumonia, myocardial infarction, renal failure, and stroke), and recovery time (intubation time, ICU stay, and postoperative length of stay) was assessed in each EuroSCORE group. EuroSCORE was well correlated with mortality, total incidence of major complications, heart failure, renal failure, stroke, pneumonia and mediastinitis, and three parameters of recovery time. Postoperative myocardial infarction and incidence of bleeding were not correlated with EuroSCORE. EuroSCORE can predict not only mortality but also postoperative complications and recovery time.

[Off-pump coronary artery bypass grafting for angina pectoris with coronary artery aneurysm due to kawasaki disease: report of a case]

We report a 27-year-old woman who underwent off-pump coronary artery bypass grafting (OPCAB) for angina pectoris with coronary artery aneurysm due to Kawasaki disease. At the age of 3, she was diagnosed as Kawasaki disease with coronary artery aneurysms in the right coronary artery and the left anterior descending artery. She was medically followed-up since then Because an enlarged aneurysm and a stenotic lesion were recognized in the right coronary artery, operation was indicated. In operation, the right coronary artery was ligated at the inflow and the outflow of the aneurysm. OPCAB was also conducted with the right internal thoracic artery anastomosed to the right coronary artery. Postoperative course was uneventful, and she was discharged at the day 5 after operation. Revascularization using arterial grafts, especially the internal thoracic arteries, may be the choice for young patients to expect a good patency rate in the long-term.

[Off-pump coronary artery bypass grafting as standard operation; surgical strategies and results]

We report the clinical results of 799 cases of isolated coronary artery bypass grafting (CABG) performed during the recent 5 years. We performed off-pump CABG (OPCAB) as standard operation, in which arterial grafts were mainly used. The mean number of distal anastomoses was 3.6 +/- 1.4 per patient Four hundred and fifty-five cases (57.0%) were done only with arterial grafts. Bilateral internal thoracic arteries were used in 326 cases. The mean number of saphenous vein grafts was 1.6 +/- 0.8 per patient. Continuous hemodiafiltraion (CHDF) was performed in 22 cases (2.8%) postoperatively. Among the OPCAB cases, 10 cases (1.3%) were converted to on-pump CABG. There were 7 cases (0.9%) of hospital death. The mean length of postoperative hospital stay was 10.2 +/- 5.3 days. The ratio of the patients with left main trunk disease and that of the patients who required postoperative CHDF increased year by year. The mean length of postoperative hospital stay decreased every year, and the reduced length was 2.7 days in the 5 years (8.7+/- 3.6 days in 2007). It is expected that patients who have severe calcified lesions or who are on hemodialysis may increase in the near future. In such cases, CABG rather than percutaneous catheter intervention may be suitable for revascularization. Therefore, not only appropriate choice of treatment strategies, but also accurate surgical techniques may become more importance.

A novel approach to restore atrial function after the maze procedure in patients with an enlarged left atrium

OBJECTIVE

Left atrial (LA) volume reduction surgery concomitant with the maze procedure has been reported to facilitate sinus rhythm recovery even in patients with refractory atrial fibrillation (AF) with an enlarged LA. However, it is unknown whether the procedures can also restore effective atrial function of the enlarged LA with over-stretched myocardium.

METHODS

The maze procedures in association with mitral valve surgery were performed to 57 AF patients with an enlarged LA (LA diameter >or=60mm). Among them, 32 patients had concomitant LA volume reduction surgery (VR group). Another 25 patients did not have the volume reduction (control group).

RESULTS

Three months postoperatively LA end-diastolic volume (LAEDV, ml) assessed by magnetic resonance (MR) imaging was larger in the VR group than that in the control group (291+/-117 vs 223+/-81 ml, p<0.05). Postoperatively, sinus rhythm recovery rate was better (84 vs 68%, p<0.05) and LAEDV was drastically smaller (118+/-48 vs 203+/-76 ml, p<0.001) in the VR group than those in the control group. Among the patients with sinus rhythm recovery in both groups, LA contraction ejection fraction (%) improved in the VR group but not in the control group (22.3+/-7.8 vs 10.3+/-4.7%, p<0.001).

CONCLUSIONS

The LA volume reduction surgery concomitant with the maze procedure restored contraction of the enlarged LA; however, the maze procedure alone did not restore LA contraction in spite of successful sinus rhythm recovery. LA volume reduction surgery may be desirable to the patients with refractory AF with over-stretched LA.

Coronary Angiography by 64-Detector Row Computed Tomography Using Low Dose of Contrast Material with Saline Chaser

OBJECTIVE

To assess the influence of total injection volume on thoracic great vessels and coronary arteries enhancement in 64-detector row computed tomography (CT) coronary angiography using low dose of contrast material.

METHODS

Sixty patients underwent cardiac CT (64 x 0.5 mm, 0.4 rot/s) using 40 mL of contrast material (350 mg of Iodine per milliliter) in 30 patients and 50 mL in 30 patients. Computed tomography densities (Hounsfield units) in ascending aorta, descending aorta, and main pulmonary artery were measured at every second with the time of CT data acquisition recorded in each reconstructed image. Computed tomography densities of proximal and distal coronary arteries were also measured. Differences in CT densities between 40 and 50 mL contrast material were assessed with the Student t test. In addition, the relation between the injection volume (mL) of contrast material per kilogram body weight and contrast enhancement in coronary arteries was studied.

RESULTS

The average attenuations in the ascending and descending aorta and coronary arteries were significantly lower in 40-mL group than in 50-mL group (<0.05). In addition, the average attenuations in the pulmonary artery were significantly lower in 40-mL group than 50-mL group (<0.01). Every patient with the total injection volume of more than 0.9 mL/kg body weight showed a contrast enhancement more than 250 Hounsfield units.

CONCLUSIONS

The reduction of total injection volume lowered the enhancement of thoracic great vessels and coronary arteries in 64-detector row cardiac CT. The injection volume of at least 0.9 mL/kg body weight was necessary for a steady contrast enhancement in coronary arteries.

Chordal "translocation" for functional mitral regurgitation with severe valve tenting: an effort to preserve left ventricular structure and function

OBJECTIVE

The chordal cutting method is performed for mitral valve tenting in functional mitral regurgitation, such as ischemic mitral regurgitation. However, the method may interfere with the mitral valvular-ventricular continuity. To maintain the continuity and the natural force direction between the papillary muscles and the mitral annulus after chordal cutting, we developed "translocation" of the secondary chordae tendineae.

METHODS

Six mongrel dogs had sonomicrometry crystal markers implanted in the left ventricle, mitral annulus, and papillary muscle tips. After the secondary chordae tendineae of the anterior mitral leaflet from each papillary muscle were resected, each papillary muscle tip was connected to the mid-anterior mitral annulus with 4-0 polypropylene sutures, and then the sutures were taken out of the left atrium to control the chordal tension. The condition under which the artificial chordae were released was defined as "redundant." The chordal tension of 15 g of weight was defined as "taut," whereas the tension for 2-mm chordal shortening after "taut" was defined as "tight." After the dogs were weaned from cardiopulmonary bypass, hemodynamic and 3-dimensional data were acquired under the condition of "redundant," and then "taut," "tight," and "redundant."

RESULTS

End-systolic elastance increased from 1.81 +/- 0.24 mm Hg/mL to 2.69 +/- 0.89 mm Hg/mL (P = .015) between "redundant" and "taut," and this was maintained between "taut" and "tight." However, preload recruitable stroke work increased from 41.3 +/- 12.0 mm Hg to 58.1 +/- 19.7 mm Hg (P = .005) between "redundant" and "taut," and was reduced to 51.7 +/- 22.9 mm Hg (P = .037) between "taut" and "tight."

CONCLUSION

"Translocation" of the secondary chordae tendineae after chordal cutting improved left ventricular systolic function compared with simple chordal cutting.

Sustained-release erythropoietin ameliorates cardiac function in infarcted rat-heart without inducing polycythemia

BACKGROUND

The usefulness of sustained-release erythropoietin for improving left ventricular (LV) function without polycythemia was evaluated in a rat chronic myocardial infarction model.

METHODS AND RESULTS

Four weeks after left coronary artery ligation, 50 Sprague-Dawley rats were assigned to 5 groups (n=10, each). Control group had a gelatin sheet (20x20 mm) containing saline applied to the infarct area, whereas the 4 treatment groups had gelatin sheets incorporating erythropoietin 0.1 U, 1 U, 10 U and 100 U, respectively. Endpoint measurements performed at 8 weeks after the coronary ligation revealed that the fractional area change was larger for erythropoietin 1 U and 10 U than in the other 3 groups. The LV end-systolic elastance and the time constant of isovolumic relaxation were better for erythropoietin 1 U and 10 U than in the other 3 groups. The density of vessels larger than 50 microm in diameter was the highest in the erythropoietin 1 U group. The number of red blood cells was significantly increased in groups receiving erythropoietin 10 U and 100 U.

CONCLUSIONS

Gelatin hydrogel sheets incorporating 1 U erythropoietin improved LV function without inducing polycythemia in a rat chronic myocardial infarction model.

Successful aortic valve replacement for Heyde syndrome with confirmed hematologic recovery

Aortic valve stenosis can be complicated by recurrent gastrointestinal bleeding, particularly that due to angiodysplasia, also called Heyde syndrome. Recently, acquired type 2A von Willebrand disease, which is characterized by the loss of the large multimer of von Willebrand factor by the shear stress of aortic valve stenosis, was reported to be associated with this hemorrhagic syndrome. A 78-year-old woman, with severe aortic stenosis, presented with advanced anemia due to recurrent gastrointestinal bleeding and was diagnosed Heyde syndrome. By perioperative supplementation of von Willebrand factor and factor VIII, aortic valve replacement was safely performed without gastrointestinal bleeding. After the operation, the multimer of von Willebrand factor was normalized and thereafter no gastrointestinal bleeding occurred. This case reports the successful aortic valve replacement for Heyde syndrome, with confirmed hematologic recovery.

A Novel Approach to Therapeutic Angiogenesis for Patients With Critical Limb Ischemia by Sustained Release of Basic Fibroblast Growth Factor Using Biodegradable Gelatin Hydrogel An Initial Report of the Phase I-IIa Study

BACKGROUND

Limb ischemia remains a challenge. To overcome shortcomings or limitations of gene therapy or cell transplantation, a sustained release system of basic fibroblast growth factor (bFGF) using biodegradable gelatin hydrogel has been developed.

METHODS AND RESULTS

A phase I-IIa study was performed, in which 7 patients had critical limb ischemia. They were intramuscularly injected with 200 microg of bFGF-incorporated gelatin hydrogel microspheres into the gastrocnemius of the ischemic limb. End-points were safety and feasibility of treatment after 4 and 24 weeks. One patient was excluded from the study for social reasons, but only after symptomatic improvements. In the evaluation of the other 6 patients, significant improvements were observed in the distance walked in 6 min (295+/-42 m vs 491+/-85 m for pretreatment vs after 24 weeks, p=0.023) and in transcutaneous oxygen pressure (53.5+/-5.2 mmHg vs 65.5+/-4.0 mmHg, p=0.03). The rest pain scale also improved (3.5+/-0.2 vs 1.0+/-0.6, p=0.022). The ankle-brachial pressure index improved at 4 weeks but not at 24 weeks. Among 5 patients who had a non-healing foot ulcer, the ulcer was completely healed in 3 patients, reduced in 1, and there was no change in 1 patient at 24 weeks. The blood levels of bFGF were undetected or within the normal level in all patients.

CONCLUSIONS

The sustained release of bFGF from gelatin hydrogel might be simple, safe, and effective to achieve therapeutic angiogenesis because it did not need genetic materials or collection of implanted cells, and because it did not have any general effects, which was supported by there being no elevation of the bFGF serum level.

A novel atrial volume reduction technique to enhance the Cox maze procedure: Initial results

OBJECTIVE

Large left atrial diameter is reported to be a predictor for recurrent atrial fibrillation after the Cox maze procedure, and left atrial diameter by itself influences the chance of sinus rhythm recovery, as well as maintenance of sinus rhythm. However, additional cut-and-sew procedures to decrease left atrial diameter extend operative time and can cause bleeding. Thus we developed a no-bleeding, faster, and therefore less invasive left atrial volume reduction technique to enhance the Cox maze procedure.

METHODS

The modified Cox maze III procedure with cryoablation or the left atrial maze procedure in association with mitral valve surgery was performed in 80 patients with atrial fibrillation and enlarged left atria (> or =60 mm). Among them, 44 patients had the concomitant volume reduction technique (VR group); continuous horizontal mattress sutures for left atrial plication were placed on the left atrial wall along the pulmonary vein isolation line. Cryoablation was applied to the suture line so that the plicated left atrium is anatomically and electrically isolated. Another 36 patients did not have the volume reduction technique (control group).

RESULTS

The VR group had preoperative left atrial diameters similar to those of the control group (67.1 +/- 7.8 vs 64.5 +/- 6.7 mm) and a longer preoperative duration of atrial fibrillation (14.1 +/- 5.4 vs 9.5 +/- 5.1 years, P < .05) but had smaller postoperative left atrial diameters (47.6 +/- 6.3 vs 62.1 +/- 7.9 mm, P < .01). There were no differences in mean crossclamp/bypass time and chest tube drainage for 12 hours between the groups. Twelve months after surgical intervention, the sinus rhythm recovery rate of the VR group was better than that of the control group (90% vs 69%, P < .05).

CONCLUSIONS

Even in patients with long-standing atrial fibrillation and an enlarged left atrium, maze procedures concomitant with the novel left atrial volume reduction technique improved the sinus rhythm recovery rate without increasing complications. Although further study with a larger number of patients and a longer follow-up period is needed, this safe and thus far potent technique that catheter-based ablation cannot copy might extend indication of the Cox maze procedure for patients with tough atrial fibrillation.

Insulin-like growth factor-1 enhances the efficacy of myoblast transplantation with its multiple functions in the chronic myocardial infarction rat model

BACKGROUND

Myoblast transplantation (Tx) is promising for the improvement of cardiac function in ischemic cardiomyopathy. Insulin-like growth factor-1 (IGF-1) has anti-apoptotic and angiogenic effects, and induces myocyte hypertrophy. Our hypothesis is that topical and slow-release IGF-1 enhances the efficacy of Tx through its multiple functions.

METHODS

Four weeks after coronary artery ligation, Lewis rats were divided into four groups: (1) IGF-1+Tx, injection of 6 x 10(6) myoblasts into the infarcted area with placement of an IGF-1-impregnated sheet on the left ventricular (LV) free wall; (2) Tx, Tx alone; (3) IGF-1, IGF-1 sheet alone; and (4) control. We measured cardiac function and performed immunohistochemical examinations.

RESULTS

At 4 weeks after treatment, LV diastolic dimension was the smallest, end-systolic elastance was the highest, and tau was the smallest in the IGF-1+Tx group. The graft volume in the IGF-1+Tx group was 3-fold larger than in the Tx group. One day after transplantation, TUNEL-positive donor cells were fewer in the IGF-1+Tx than in the Tx group. Western blot analysis demonstrated that the phosphorylation of Akt increased and the expression of Bax decreased in the transplanted area of IGF-1+Tx rats compared with Tx rats. The vascular density in the peri-infarcted area was larger in IGF-1+Tx than in Tx rats. The mean diameter of graft-derived myotubes was larger in IGF-1+Tx than in Tx animals.

CONCLUSIONS

IGF-1 increases the graft volume and enhances the efficacy of Tx in the chronic myocardial infarction model due to its multiple effects of preventing apoptosis, inducing angiogenesis, and promoting myoblast growth.

Cough reflex by ventricular premature contractions

A 72-year-old man was referred for further assessment of a chronic cough. He noticed an association between the episodes of coughing and palpitations. Electrocardiography (ECG) revealed normal sinus rhythm and sporadic unifocal ventricular premature contractions (VPCs). Each cough was preceded by a premature beat. Continuous wave Doppler echocardiography revealed a VPC-induced transient increase in the pulmonary artery blood flow. He was successfully treated for VPCs with oral disopyramide, resulting in subsidence of both the coughing and palpitations. We suspect that the VPC-induced hemodynamic changes in the pulmonary circulation might be responsible for coughing in our patient. Premature contractions should be considered as a possible cause of chronic dry cough in the clinical setting.

Administration of control-released hepatocyte growth factor enhances the efficacy of skeletal myoblast transplantation in rat infarcted hearts by greatly increasing both quantity and quality of the graft

BACKGROUND

We investigated whether simultaneous administration of control-released hepatocyte growth factor (HGF) enhances the efficacy of skeletal myoblast (SM) transplantation (Tx) through its antiapoptotic, angiogenic, and antifibrotic effects in myocardial infarction (MI).

METHODS AND RESULTS

Forty-eight Lewis rats with chronic MI were divided into 4 groups. In Group I (n=14), neonatal SMs (5 x 10(6)) were transplanted in the MI area with a gelatin sheet incorporating 40 microg (1 g/L) of HGF applied. Group II (n=14) had SM Tx and placement of a saline sheet. Groups III (n=10) and IV (n=10) had culture medium injection plus HGF and saline sheet application, respectively. Four rats each from Groups I and II were sacrificed at day 1 for TUNEL assay on donor SMs. The percentage of TUNEL-positive donor cells was much lower in Group I than in Group II (P<0.05). At 4 weeks, in Group I, left ventricular diastolic dimension was smallest in echocardiography, end-systolic elastance was highest, and tau was the lowest (both P<0.0005 in ANOVA) in cardiac catheterization. Vascular density inside the graft was higher in Group I than in Group II (P<0.0001). The percentage of fibrotic area inside the graft was smaller in Group I than in Group II (P<0.001). The graft volume as estimated by fast skeletal myosin heavy chain-positive areas was approximately 7-fold larger in Group I than in Group II (P<0.0001).

CONCLUSIONS

In SM Tx, HGF can greatly increase the graft volume and vascularity and reduce fibrosis inside the graft, which enhances the efficacy of SM Tx to infarcted hearts.

Repeated Implantation is a More Effective Cell Delivery Method in Skeletal Myoblast Transplantation for Rat Myocardial Infarction

BACKGROUND

Several clinical trials are underway to determine whether autologous skeletal myoblast transplantation is an effective and safe therapeutic strategy for severe heart failure due to myocardial infarction (MI). It remains unclear whether repeated skeletal myoblast implantation is a feasible and effective cell delivery method for the infarcted myocardium.

METHODS AND RESULTS

Four weeks after a coronary ligation, male syngeneic Lewis rats were assigned to 3 treatment groups: 3 episodes of skeletal myoblasts (6x10(6)) transplantation (group I), a bolus transplantation of myoblasts (18x10(6)) (group II), or culture medium injection (group III). Eight weeks after the first treatment, echocardiography, cardiac catheterization and histological examination were performed to compare the therapeutic effects on left ventricular (LV) systolic and diastolic functions, and the engrafted myoblast volume. Repeated myoblast implantation significantly improved LV function and resulted in significantly larger engrafted volume and LV contractility compared with a bolus transplantation with the same number of myoblasts.

CONCLUSIONS

Repeated skeletal myoblast transplantation is a safe and effective therapeutic strategy for the infarcted myocardium.

Beta-adrenergic stimulation does not activate Na+/Ca2+ exchange current in guinea pig, mouse, and rat ventricular myocytes

The effect of beta-adrenergic stimulation on cardiac Na(+)/Ca(2+) exchange has been controversial. To clarify the effect, we measured Na(+)/Ca(2+) exchange current (I(NCX)) in voltage-clamped guinea pig, mouse, and rat ventricular cells. When I(NCX) was defined as a 5 mM Ni(2+)-sensitive current in guinea pig ventricular myocytes, 1 microM isoproterenol apparently augmented I(NCX) by approximately 32%. However, this increase was probably due to contamination of the cAMP-dependent Cl(-) current (CFTR-Cl(-) current, I(CFTR-Cl)), because Ni(2+) inhibited the activation of I(CFTR-Cl) by 1 microM isoproterenol with a half-maximum concentration of 0.5 mM under conditions where I(NCX) was suppressed. Five or ten millimolar Ni(2+) did not inhibit I(CFTR-Cl) activated by 10 microM forskolin, an activator of adenylate cyclase, suggesting that Ni(2+) acted upstream of adenylate cyclase in the beta-adrenergic signaling pathway. Furthermore, in a low-extracellular Cl(-) bath solution, 1 microM isoproterenol did not significantly alter the amplitude of Ni(2+)-sensitive I(NCX) at +50 mV, which is close to the reversal potential of I(CFTR-Cl). No change in I(NCX) amplitude was induced by 10 microM forskolin. When I(NCX) was activated by extracellular Ca(2+), it was not significantly affected by 1 microM isoproterenol in guinea pig, mouse, or rat ventricular cells. We concluded that beta-adrenergic stimulation does not have significant effects on I(NCX) in guinea pig, mouse, or rat ventricular myocytes.

Residual fibrosis affects a long-term result of left ventricular volume reduction surgery for dilated cardiomyopathy in a rat experimental study

OBJECTIVES

The aim of this study is to evaluate the relationship between left ventricular (LV) wall property and the results of LV volume reduction surgery (LVR) to treat dilated cardiomyopathy (DCM) in an experimental model.

METHODS

DCM was introduced in 18 Lewis rats by autoimmunization with cardiac myosin. Among them, 12 rats underwent LVR and the rest were served as controls. They were subjected to echocardiography and cardiac catheterization for dimensional and functional measurements. The animals were sacrificed 4 weeks after surgery, and the fraction of myocardial fibrosis was calculated in 4 divided parts of the LV wall.

RESULTS

Percent fibrosis varied widely from 4.7 to 45.2%. LV volume reduction surgery improved cardiac function immediately after surgery in all rats (Emax, 0.28+/-0.14 to 0.48+/-0.18 mmHg/microl; LV end-diastolic pressure, 21.0+/-6.1 to 13.3+/-5.1 mmHg, P<0.05, respectively). Four weeks later, 6 hearts remained in good shape with smaller LV end-diastolic dimension (Dd) than baseline values (LV Dd, 9.7+/-0.6mm; fractional area change (FAC), 40.3+/-8.4%) and the other 6 had more redilation in diameter and more deterioration in function than baseline values (LV Dd, 10.9+/-0.6mm; FAC, 25.8+/-6.9%; P<0.05, respectively). Percent fibrosis in the septum differed 11.1+/-3.4 vs. 27.8+/-2.8% between the two groups (P<0.01). There was a significant correlation between the ratio of LV redilatation after surgery and percent fibrosis in the septum (r=0.951, P<0.01).

CONCLUSIONS

Although the initial benefit of LVR was confirmed, the long-term result was affected by the amount of residual fibrosis. This information suggests that surgical site selection is important to achieve a good result of LV restoration surgery for DCM.

Control-Released Hepatocyte Growth Factor Prevents the Progression of Heart Failure in Stroke-Prone Spontaneously Hypertensive Rats

BACKGROUND

We have developed a hepatocyte growth factor (HGF)-incorporating gelatin hydrogel sheet (HGF sheet), which was designed to release HGF more than 2 weeks in vivo. The present study investigated whether the HGF sheet could prevent the progression of heart failure in stroke-prone spontaneously hypertensive rats.

METHODS

Stroke-prone spontaneously hypertensive rats at the age of 25 weeks received placement of an HGF sheet on the left ventricular free wall (HGF, n = 10) or sham-operation (control, n = 10). All animals were followed up with Doppler echocardiography during the next 4 weeks and then underwent histologic analysis. The influence of the hydrogel sheet alone was assessed by echocardiography and left ventricular pressure measurements. Survival study was performed (each group, n = 11) at the age of 30 weeks.

RESULTS

There were two deaths in the control group and no deaths in the HGF group during the 4 weeks. Fractional shortening was significantly higher, and left ventricular diastolic dimension was significantly smaller in the HGF than in the control group. The slope of the peak early diastolic filling velocity and the ratio of that slope to the slope of the peak filling velocity at atrial contraction were significantly lower in the HGF than the control group. Myocardial fibrosis was lower and capillary density was significantly higher in the HGF than the control group. Placement of the hydrogel sheet alone did not affect any cardiac function compared with sham operation. The survival rate at 10 weeks after the surgery was much higher in the HGF than the control group.

CONCLUSIONS

The HGF sheet improves cardiac function, reverses left ventricular remodeling, and markedly improves survival in spontaneously hypertensive rats. These beneficial effects are associated with angiogenesis and reduced fibrosis in the left ventricular myocardium.

Primary Cardiac Lymphoma Demonstrated by Delayed Contrast-Enhanced Magnetic Resonance Imaging

Delayed contrast-enhanced magnetic resonance (MR) imaging that nullifies the signal of normal myocardium produces great differences in myocardial signal intensity between normal and infarcted myocardium. A case of primary cardiac lymphoma is presented in which delayed contrast-enhanced MR imaging clearly identified the localization and extension of a lymphoma infiltrating the myocardium.

Beneficial effect of candesartan treatment on cardiac autonomic nervous activity in patients with chronic heart failure: simultaneous recording of ambulatory electrocardiogram and posture

BACKGROUND

Reclining in the right lateral decubitus position in chronic heart failure (CHF) is a self-protective mechanism for normalizing impaired cardiac autonomic nervous activity (CANA).

HYPOTHESIS

Candesartan, an angiotensin II receptor blocker, exerts beneficial effects on CANA and postural preferences in patients with CHF.

METHODS

We studied 15 patients with CHF due to coronary artery disease. Cardiac autonomic nervous activity was assessed using spectral heart rate variability (HRV) analysis based on 24-h ambulatory electrocardiogram monitoring before and after an 8-week treatment with candesartan. The patients' posture was simultaneously recorded using a specially devised detector, as the right (R) or left (L) lateral decubitus or supine (S) positions, to evaluate postural modulations of CANA. Normalized high-frequency (0.15 to 0.40 Hz) power (nHF) and the low-frequency (0.04 to 0.15 Hz)/high-frequency power ratio (LF/HF) were used as indices of vagal activity and sympathovagal balance, respectively.

RESULTS

When HRV was analyzed in each position, CANA was changed in L and S, but not in R, from sympathetic to parasympathetic prevalence by the treatment (R, nHF, 50 +/- 20 vs. 52 +/- 19 nu, p = 0.87; LF/HF, 1.39 +/- 1.11 vs. 1.32 +/- 1.32, p =0.93; L, nHF, 28 +/- 13 vs. 47 +/- 19 nu, p = 0.019; LF/HF, 3.34 +/- 2.48 vs. 1.56 +/- 1.39, p = 0.029; S, nHF, 38 +/- 17 vs. 53 +/- 16 nu, p = 0.0023; LF/HF, 2.43 +/- 2.21 vs. 1.03 +/- 0.59, p = 0.025). The fractions of the time in R and L were decreased and increased, respectively, by the treatment (R, 40 +/- 30 vs. 18 +/- 24%, p = 0.0018; L, 11 +/- 20 vs. 27 +/- 26%, p = 0.025).

CONCLUSIONS

In patients with CHF, candesartan treatment improves cardiac autonomic balance, and the preference for the right lateral decubitus position disappears after the treatment.

Right lateral decubitus position reduces QT dispersion in patients with chronic heart failure

A greater QT dispersion in patients with chronic heart failure (CHF) appears to be a non-invasive marker of susceptibility to malignant ventricular arrhythmias. We evaluated whether QT dispersion in CHF patients is modified by the patients' recumbent position. In 12 CHF patients, and age and sex-matched 12 normal subjects, a single 12-lead surface ECG was recorded in each postural position [left lateral decubitus position (L), supine position (S), and right lateral decubitus position (R)]. In normal subjects, the QT dispersion was comparable in the three recumbent positions [L: 47+/-15 (SD) ms, S: 40+/-9 ms, R: 38+/-14 ms, P=NS]. In contrast, in CHF patients, QT dispersion was significantly shorter in R than those in L and S (L: 93+/-42 ms*, S: 81+/-29 ms*, R: 63+/-24 ms, *P <.05 vs. R). In conclusion, reclining in R reduces the prolonged QT dispersion in CHF patients.

Therapeutic angiogenesis by the controlled release of basic fibroblast growth factor for ischemic limb and heart injury: toward safety and minimal invasiveness

We review our studies on therapeutic angiogenesis using basic fibroblast growth factor (bFGF) released in a controlled manner from biodegradable gelatin hydrogel (GH). The bFGF-GH was intramuscularly injected in rabbits with limb ischemia. The group treated with bFGF showed an increase in tissue blood flow under laser Doppler imaging and histology showed a greater vascular density compared with controls. Also, bFGF-GH was subepicardially injected into old heart infarcts in rats. In the group treated with bFGF, improved left ventricular function was shown by echocardiography and cardiac catheterization, increased regional blood flow in the peri-infarct area was detected by pinhole single-photon emission computed tomography using (201)Tl, and increased vascular density was demonstrated by histology. In rabbits with acute myocardial infarction, the heart was wrapped with the omentum (including the gastroepiploic artery) and a bFGF-GH sheet was applied. Postoperative assessment revealed rich communication from the gastroepiploic artery to the coronary artery and improved cardiac function. The controlled release of bFGF was effective for both limb and heart ischemia and is considered to be suitable for clinical use because its application in animals was feasible and safe with minimal invasiveness.